Mr Morrison will use the figures to outline the full impact of Labor's plan to oppose $230 billion in personal income tax cuts and extract another $157 billion in higher revenue from negative gearing, dividend changes and other measures.

The government estimate puts personal tax cuts and budget management at the heart of the political debate on the second day of the campaign, as Opposition Leader Bill Shorten steps up his pledge to voters to restore health funding and cut the cost of cancer treatment.

Mr Shorten will commit $125 million to cancer research programs on Friday while accusing the government of cutting hospital spending over the past five years.

Central to the Labor campaign is a pledge to spend at least $3 billion more than the Coalition on hospitals over the next six years, including a "better hospitals fund" and $500 million to reduce waiting times for cancer treatment in public hospitals.

Speaking after a 7am visit to Governor-General Sir Peter Cosgrove to call for the House of Representatives to be dissolved, Mr Morrison asked Australians to trust him to run the economy and repair the budget, declaring "now is not the time to turn back" by handing power to Labor.

Mr Shorten countered with a pledge to lift wages and reduce inequality while urging voters to reject the "tiredness" and "instability" of the Coalition after three prime ministers in six years.

The new government costings set a baseline for the election campaign by revising an earlier estimate of $200 billion for the Labor tax policies over a decade, although only a portion of this comes from new taxes.

Urging Australians to consider the hit to their budgets from tax increases, the government estimates 2.2 million taxpayers in NSW and 1.7 million taxpayers in Victoria would be worse off over a decade from Labor's decision to block the second and third stages of the tax plan unveiled in the last two Coalition federal budgets.

While the government claims the $387 billion is in "new taxes" the biggest single item is Labor's rejection of government tax cuts in favour of a Labor alternative to offer bigger benefits to workers on lower incomes.

The figure also helps quantify the policy gulf between the two major parties, with Labor raising so much revenue it could reveal more spending on health, education and infrastructure while still adding to budget surpluses.

Labor has responded to the last week's federal budget, with its forecast of a $7.1 billion surplus next financial year, by suggesting it might be able to pay down debt faster than the government.

Treasurer Josh Frydenberg said the Treasury cost estimates showed Australia "cannot afford Labor" and that "now is not the time to return to Labor" - a key message aimed at curbing a powerful swing against the Coalition in the opinion polls.

The $387 billion includes $6.5 billion from the imposition of a higher income tax rate on workers earning more than $180,000 a year, adding 2 per cent to their marginal tax rate until 2023.

It also includes $31.5 billion from the Labor changes to negative gearing and capital gains tax, $56.8 billion from changes to dividend imputation, $27.2 billion from higher taxation on family trusts and $1.7 billion from caps on tax deductions.

Another $34 billion comes from higher taxes on superannuation including Labor proposals to tighten rules on "catch up contributions" and stop some personal super contributions being tax deductible.

Shadow treasurer Chris Bowen lashed out at the government claims after seeing a leaked copy of the Treasury costings on Thursday night, in rapid developments on the opening day of the campaign.

"Scott Morrison is never happier than when he's defending the top end of town or trying to give the banks a tax cut," Mr Bowen said.

Mr Frydenberg's office received the costings from Treasury in the wake of last week's federal budget but declined to release the full documents to The Sydney Morning Herald and The Age. Mr Bowen said they were "dodgy" costings.

In an unusual decision to call the election mid-week, Mr Morrison flew from Melbourne to Canberra on Wednesday night and visited the Governor-General before launching the campaign in Parliament House.

The writs were issued on Thursday and the electoral roll will close on Thursday of next week, April 18, the deadline for Australians to enrol to vote or amend their details at the Australian Electoral Commission.

The government also faces an April 18 deadline to reveal some of the hidden spending and savings decisions in the budget, including a $2.7 billion spending cut in 2022 which was not announced on budget day.

These and other measures must be revealed before Good Friday, April 19, because the Pre-Election Fiscal Outlook must be issued by Treasury and the Department of Finance within 10 days of the issue of the writs.

Mr Morrison insisted the election was about the future rather than the past when asked why voters should reward the Coalition for the instability that led to three prime ministers in six years.

The Liberal Party had changed its leadership rules to ensure there would be no change in leader in mid-term, he said.

"So it is crystal clear [that] at this election it is a choice between me as prime minister and Bill Shorten as prime minister," Mr Morrison said.

"You vote for me, you'll get me. You vote for Bill Shorten and you'll get Bill Shorten."

The message highlighted the confidence within the Coalition that more voters regard Mr Morrison as preferred leader, a finding also in the Ipsos opinion poll released last Monday.

The Prime Minister's core message to voters was to place their trust in him rather than take the risk of giving Mr Shorten control of the economy.

"The choice to be made by Australians on 18 May is like it always is at every election, and that is: who do you trust to deliver that strong economy which your essential services rely on?" Mr Morrison said, reprising an argument put by former Prime Minister John Howard to win the 2004 election.

Mr Shorten said Australians faced a "real and vital choice" at the election and should use their votes to put an end to a divided government.

"Do you want Labor's energy versus the government's tiredness?" he said.

"Labor's focus on the future versus being stuck in the past? Labor's positive plan for all Australians or a negative fear campaign from the other side?"

Mr Shorten will intensify his campaign on health on Friday by announcing another plank of the $2.3 billion cancer package he unveiled last week.

With health funding a core part of the opposition campaign, Labor deputy leader Tanya Plibersek reminded voters of the cuts to hospitals and schools in government's 2014 federal budget and said they remained an issue for the next term of Parliament.

While the government won 76 seats at the last election and held a narrow majority through much of the last term, it lost the seat of Wentworth after Malcolm Turnbull resigned and lost another member when Julia Banks quit the Liberals to sit as an independent.

ABC election analyst Antony Green estimates the government goes to the election with 73 seats following a redistribution in Victoria.

Mr Green estimates Labor has 72 seats as a result of the redistribution, a significant gain on the 69 seats it won at the last election.

- SMH/The Age.